Hot metal desulphurisation

Hot metal desulphurisation The hot metal produced with blast furnaces contains relatively high amounts of sulphur, which is detrimental for the mechanical properties of steel. Owing to the limited desulphurisation capacity of converter processes, it is commonplace to conduct hot metal desulphurisation in a ladle or a torpedo car before further treatment at the meltshop. The desulphurisation reagent is typically injected through a submedged top lance.

Highlights

• A mathematical model has been developed for hot metal desulphurisation. The objective was to derive a model, which accounts for the effects of main technological and operational parameters on the desulphurisation efficiency. The model calculates the desulphurisation rate based on the basis of thermodynamic driving force and relevant mass transfer resistances. The model can be employed for studying effect of the main operating and technological parameters (e.g. reagent composition, size distribution and injection rate) on the efficiency of desulphurisation.
• Data-driven parametrised reaction model, in which the rate parameters are optimised with an genetic algorithm.
• A genetic algorithm based variable selection method was developed for prediction of primary and secondary hot metal desulphurisation
  
• High temperature experiments have been carried out to investigate kinetics of metal-slag reactions during and after the hot metal desulphurisation.

Selected publications

• T. Vuolio, V.-V. Visuri, A. Sorsa, S. Ollila, and T. Fabritius, “Application of a genetic algorithm based model selection algorithm for identification of carbide-based hot metal desulfurization,” Applied Soft Computing, vol. 92, article 106330, 2020.
• V.-V. Visuri, T. Vuolio, T. Haas, and T. Fabritius, “A Review of Modeling Hot Metal Desulfurization,” Steel Research International, vol. 91, no. 4, 2020. 1900454.
• T. Vuolio, V.-V. Visuri, A. Sorsa, T. Paananen, and T. Fabritius, “Genetic Algorithm-Based Variable Selection in Prediction of Hot Metal Desulfurization Kinetics,” Steel Research International, vol. 90, no. 8, 2019. 1900090
• T. Vuolio, V.-V. Visuri, T. Paananen, and T. Fabritius, “Identification of Rate, Extent and Mechanisms of Hot Metal Resulfurization with CaO–SiO2–Na2O Slag Systems,” Metallurgical and Materials Transactions B, vol. 50, no. 4, pp. 1791–1807, 2019
  
• V.-V. Visuri, P. Sulasalmi, T. Vuolio, T. Paananen, T. Haas, H. Pfeifer, and T. Fabritius, "Mathematical Modelling of the Effect of Reagent Particle Size Distribution on the Efficiency of Hot Metal Desulphurisation", Proceedings of the 4th European Steel Technology and Application Days, Steel Institute VDEh, Düsseldorf, Germany, 2019.
• T. Vuolio, V.-V. Visuri, S. Tuomikoski, T. Paananen, and T. Fabritius, "Data-Driven Mathematical Modeling of the Effect of Particle Size Distribution on the Transitory Reaction Kinetics of Hot Metal Desulfurization," Metallurgical and Materials Transactions B, vol. 49, no. 5, pp. 2692–2708, 2018.

Theses instructed

• T. Ranto, “The effect of metal-slag reactions on hot metal desulfurization – a review of experimental studies (in Finnish)“, Bachelor’s thesis, University of Oulu, in progress.
• T. Vuolio, "Model-based identification and analysis of hot metal desulphurisation", Doctoral thesis, University of Oulu, 2021.
• L. Aho, "Laboratory-scale experimental research methods of hot metal desulfurization (in Finnish)", Bachelor’s thesis, University of Oulu, 2020.
H. Tähtilä, ”A study on the properties of initial slag in hot metal desulphurisation in laboratory scale with crucible experiments”, Master’s thesis, University of Oulu, in progress.
• P. Pekuri, "Initial Slag in Primary Desulphurisation of Hot Metal", Master's thesis, University of Oulu, 2020.
• P. Lehtonen, "Experimental Investigation of Hot Metal Desulphurisation", Master's thesis, University of Oulu, 2017.
• T. Vuolio, "Improvement potential of primary hot metal delsulphurization", Master's thesis, University of Oulu, 2017.